Toolholder



April 26, 1949. 'T E. FRISCO 2,468,396

TOOLHOLDER Filed April 26, 1946 4 5 Sheets-Sheet l INVENTOR.

THEODORE E. FiE/SCO A ril 26, 1949.

T. E. FRISCO 2,468,396 v TOOLHOLDER Filed April 26, 1946 I i I JNVENTOR. THEODORE 5 FIE/5C0 A TTOENEYS s Sheets-Sheet 2 Patented Apr. 26, 1949 UNITED STATES PATENT OFFICE 9 Claims.

This invention is directed to improvements in devices commonly referred to as floating tool holders. This invention is a continuation in part of application Serial No. 546,037 filed July 21, 19 4, by the present inventor.

It is an object of this invention to support a tool such as a reamer, drill or tap for floating or hunting movement, which movement may be an angular deviation of the tool axis from the axis of the shank of the tool holder, as well as a lateral offset of the two axes. I am aware that the prior art discloses tool holders which permit both angular and lateral motion. Many of these devices are unsatisfactory for use in tapping operations because the plane of ofiset motion of the holder is not perpendicular to the axis of shank rotation. In such an arrangement, when both lateral and angular ofisets are present and the tool is rotated, the shank imparts a given cyclic axial oscillation to the tool holder thereby destroying the accuracy of the work in case a tapping operation is being effected.

It is another object of my invention to provide a floating tool holder which is made up of simple and rugged parts, the parts being easy to manufacture and providing a positive drive with a minimum of wear and breakage in use.

Another object of my invention is to provide means whereby the tool can be firmly locked or secured in any combination of angular and offset positions within the limits of motion of the tool.

Other objects and advantages of my invention will appear in the following detailed description of preferred embodiments.

In the drawings:

Fig. 1 illustrates an embodiment of my invention described in detail in the cited application, Serial No. 546,037, filed July 21, 1944;

Fig. 2 is a sectional view taken through an improved embodiment of my invention, the section being taken on line 2-2 of Fig. 3;

Fig. 3 is a transverse section taken on the line 33 of Fig. 2;

Fig. 4 is a section like that of Fig. 2 except that it is taken on a line 90 therefrom as indicated at 4-4 of Fig. 3;

Fig. 5 is a longitudinal section taken through a modified form showing certain additional features;

Fig. 6 is a partial section through another modification showing a modified coupling block; and

Fig. 7 is an end view of the coupling block in support shown in Fig. 6 with the tool holder removed.

The tool holder shown in Fig. 1 is that described in detail in the parent application and will only be briefly described here. It includes four major parts, a shank S for insertion in drill press or head stock of the lathe or other machine tool, a tool holder T, a coupling block C to provide driving connection between the shank and tool holder, and a barrel B to retain the parts in assembled relationship. Shank S has a body section I which may be formed to fit the machine tool with which the device is used. It may include an enlarged head portion which is threaded as at 2. The head is transversely slotted as at 3 to receive a driving rib 4 formed on the coupling member 0. Coupling member C also has ears 8 which drive, by means of grooves 9, the spherical head ll! of the tool holder T. Ball 1 provides for thrust and permits angular motion of the tool holder relative to the shank. Socket ll receives a tool such as a tap or reamer.

Barrel B is formed with a shoulder portion 12 which urges concave spherical ring against the spherical portion of the tool holder T. Spring [4 rests against a washer l5 which, in turn, is retained by a shoulder portion I6 of the barrel B, the spring serving to maintain alignment of the parts when the barrel B is loosened.

The preferred embodiment illustrated in Fig. 2 has the same four basic parts, a shank S, tool holder T with a spherical head, a coupling member C and a barrel B. The shank S may have a tapered portion as at 20 to fit into the conventional tapered sleeve. The enlarged head portion 2| terminate in a fiat surface 22. The head portion is formed with sockets 23 to receive a plurality of springs 24 which tend to separate the shank and the tool holder T when the barrel B is loosened and tend to maintain parts in alignment. The barrel may be threaded to the head as at 25 and the head may be provided with an annular groove 26 so that a set screw 26a threaded into the barrel may look the barrel to the head. A transverse groove 21 is provided in the head of the shank to receive with a sliding fit the coupling block 0.

As seen in Fig. 3, the coupling block 0 may be nothing more than a square member apertured to receive a thrust ball 31 loosely. Tool holder T has an enlarged portion formed with an external spherical surface 28 and has a socket portion 29 and a set screw 30 in order to mount the tool. Barrel B has threads 3! to engage those on the head of the shank and it is provided with retaining flange 32 which may press against a'bushing 33 which, in turn, engages a centering ring 34 formed with a concave spherical surface complementary to the surface 28 on the tool holder. The holder T is provided with a transverse slot 36 to receive the coupling member C and when the parts are assembled the slots 36 in 22 are placed at 90 to one another. The construction of the headed portion of the tool holder and shank and the relationship of the slots and coupling member to one another will be made clear by a comparison of Figs. 2 and 4 which are sections taken 90 apart.

In operation, an examination of Figs. 2 -'l will make clear the fact that the angular motion of the tool holder T relative to the shank Shas for its center the center of the thrust ball 31; Likewise, axial ofiset of the holder from the shank can take place across a surface on the shank and perpendicular thereto rega dless of angular position of the tool holder T relative to the shank S. In this construction there is no tendency for the tool holder, when it is both angularly and laterally offset, and when it is rotated as in a tap,

ping operation, to alternately advance and retract the tap relative to the work, because the lateral offset motion of. the holder may occur in a plane perpendicular to the axis of the shank.

The fact that the aperture in block C fits ball 31 loosely prevents any tendency of the holder to move axially when it is both radially and angularly offset, because the ball can always move to a location providing more clearance, within the limits of the devices motion.

Itwill also be noticed that the coupling member C is of simple and rugged construction and that the slots in the shank and the tool holder are readily formed by simple milling operations. Due to the spherical ring construction as shown at 34, thethreaded barrel B can be tightened on the shank S, with which it Willv lock the tool holder T in any combination of angular and lateral offsets without interference, or distortion of the parts. After this, the set screw 25a may be tightened into the groove 26 which is made wide enough to permit normal axial motion of the barrel B in order to keep the parts in locked relationship.

The form shown in Fig. is basically like that described in connection with Figs. 2 and 4, although certain modifications are present. The shank S has a head 55 which is threaded as. before and has sockets 42 for centering springs is in a transverse slot 4! like that previously shown. The tool holder T has a flanged head id formed with a transverse slot. springs 43 merely bear against the socket in the tool holder, they may be received in the sockets such as 46 which is also true of the modifications shown in Figs. 2 and 4.

A plane surface 4'! is formed on the head of the tool holder T, against which a ring 68 is urged, the ring having an external spherical surface similar to the surface 28 shown in Fig. 2. A second ring 49 is centered and retained within the.

barrel B by an axial retaining flange 52}. There may be provided a plurality of spring-urged pins 5| fitted in sockets 52 and pressed radially. by

Instead of having thesprings 54 acting against threaded plugs 53. The external spherical surface on ring 43 has the same center as does thrust ball 3?, and by sliding against a tapered surface on the ring it the ring 48 permits angular offset of the tool holder. It is not necessary that the surface of ring at which engages the spherical surface of ring 412 be spherical, but, as shown in Figs. 2 and 4, the ring may be formed with a concave spherical surface if so desired. Except for the slight variation in the method of permitting angular motion of the tool holder, the operation of the form shown in Fig. 5 is like that shown in Figs. 2 and 4. Of course, I contemplate that the spring-urged pins 5! shown in Figs. 5 may be applied to the centering ring 34 shown in Figs. 2 and l if so desired. The axially extending springs such as springs it in Fig. 5 and springs 24 in Figs. 2 and 4 provide a certain amount of self-centering action, this action being augmented by the radially movable pins 5i.

Figs. 6 and 7 illustrate another form of coupling block which may be used in place of the block C shown in Figs. 2-5. This block applies the driving torque at a greater distance from the axis of the tool and is less subject to crushing forces than theblock C shown in Figs. 2-5. Shank S, which is only partially shown, has a head portion fit and has a pair of transverse grooves 6i and a fiat face 62 to receivea thrust of the ball. til. Block '63 has a pair of projections. or. dogs M for engagement with the slot 6! in the shank. Block 63 has a second pair of projections (it to engage a second set of grooves 61 formed in the spherical head of the tool holder T. The block is apertured as at 65 to receive the ball 3'! and the tool holder T has a concave seat 68 of slightly larger diameter than that of the ball 3 to receive and center'the ball at all times. The tool holder '1 may have an external. spherical surface til corresponding to the surface 2e shown in Figs. 2-5, or, of course, it would be possible to provide a spherical ring and flat surface such as shown in Fig. 5, these being alternative constructions. Except for the additional feature of centering the ball in the tool holder, the form shown in Figs. 6 and 7 is exactly like those shown in Figs. 2-5.

Those skilled in the art will appreciate that by permitting lateral offset totake place perpendicular. to theshank regardless of angular deviation, I produce a universal joint which has a minimum of non-uniform rotation and axial displacement of the tool holder.- Likewise, it can be seen by examining my construction that i can have a very simple means for locking the parts together in any combination of lateral and angular offsets.

I have described briefly several modifications which would be obvious to those skilled. the art and which could be made without departing from the essence of my invention. Those and other modifications may be made without departing from the spirit and scope of the invention as defined in the appendedclaims.

Having thus described; the present invention so that others skilledin theart may be able to understand and practice the same, I state that what I desire to secureby. Letters Patent isdefined; in what is claimed.

I claim:

1. In a tool holder, ashank, a holdenintermediate coupling means effectinga driving connection between said shank and holder and retainin means for maintaining said parts -in assembled relationship,v said coupling means conn prising a block carrying centrally disposed abutment means engaging facing wall portionsofsaid shank and holder at their axes and arranged to permit relative angular motion between those parts, said block having driving means, each of said facing portions of said shank and holder having a groove formed therein to receive driving means on said block, said parts being assembled with the grooves normal to one another whereby universal relative lateral displacement of said shank and holder is provided for.

2. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled relationship, said coupling means comprisin an apertured block loosely mounting centrally disposed abutment means engaging facing wall portions of said shank and holder at their axes arranged to permit relative angular motion between those parts, said block having driving means, each of said facing portions of said shank and-holder having a groove formed therein to receive driving means on said block, said parts bein assembled with the grooves normal to one another whereby universal relative lateral displacement of said shank and holder is provided for, the plane of lateral offset motion being perpendicular to the axis of said shank.

3. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintainin said parts in assembled relationship, said coupling means comprising a block carrying centrally disposed ball engaging facing portions of said shank and holder to permit relative angular motion between those parts, said block having driving means, each of said facing portions of said shank and holder having a groove formed therein to receive driving means on said block, said parts being assembled with the grooves normal to one another whereby universal relative lateral displacement of said shank and holder is provided for.

4. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled'relationship, said coupling means comprising a block carrying centrally disposed abutment means engaging facing wall portions of said shank and holder at their axes and arranged to permit relative angular motion between those parts, said block having driving means, each of said facing portions of said shank and holder having a groove formed therein to receive driving means on said block, said parts being assembled with the grooves normal to one another whereby universal relative lateral displacement of said shank and holder is provided for, said retaining means being positionable to clamp said holder to said shank in any combination of relative angular and lateral positions of said holder and shank.

5. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled relationship, said coupling means comprising a rectangular block having a centrally disposed aperture, a ball disposed in said aperture engaging facing portions of said shank and holder to permit relative angular motion between the shank and holder, each of said facing portions of said shank and holder having a groove formed therein to receive said block, said parts being assembled with the grooves normal to one another and engaging the edges of said block whereby universal relative lateral displacement of said shank and holder is provided for.

6. In a tool holder, a shank, a holder having a head portion with a spherical surface, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled relationship, said coupling means comprising a block carrying a centrally disposed ball, said ball engaging facing portions of said shank and holder to permit relative angular motion between those parts, said block having driving means, each of said facing portions of said shank and holder having a groove formed therein to receive driving means on said block, said parts bein assembled with the grooves normal to one another whereby universal relative lateral displacement of said shank and holder is provided for, a radially movable ring member engaging the spherical surface of said holder, said retaining means being positionable to force said ring against the spherical surface of said holder and clamp said holder to said shank in any combination of relative angular and lateral positions of said holder and shank.

'7. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled relationship, said coupling means comprising a block carrying centrally disposed ball engaging facing portions of said shank and holder to permit relative angular motion between those parts, one of said members engaged by said ball having a cavity to receive and position the ball, said block having driving means, each of said facing portions of said shank and holder having a groove formed therein to receive driving means on said block, said parts being assembled with the grooves normal to one another whereby universal relative lateral displacement of said shank and holder is provided for.

8. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled relationship, said coupling means comprising a block formed with centrally disposed aperture, a ball disposed in said aperture, said ball engaging facing wall portions of said shank and holder and arranged to permit relative angular motion between those parts, said block having oppositely extending driving means, each of said facing portions of said shank and holder having a groove formed therein to receive driving means on said block, said parts being assembled with the grooves normal to one another whereby universal relatively displacement of said shank and holder is provided for.

9. In a tool holder, a shank, a holder, intermediate coupling means effecting a driving connection between said shank and holder and retaining means for maintaining said parts in assembled relationship, facing portions of said shank and holder having a groove formed therein, said parts being assembled with the grooves normal to one another, said coupling means comprising block means formed with centrally disposed aperture, a ball disposed in said aperture, there being clearance between the ball and the block, said block means having a portion slidably mounted in each of said grooves, said ball engaging facing wall portions of said shank and holder and arranged to permit relative angular motion between those parts, whereby universal relative displacement of said shank and holder is Number Name Date provided for. 1,359,102 Randa; Nov. 16, 1920- TH-EODORE E. FRI C 1,431,830 Miller Oct; 10 1922 1,513,647 Spiritus Oct. 28, 1924 REFERENCES CITED 5 1,5409%? OBrien June 9, 1925 The following references are of record in the 1,566,553 1925 file of patent: NOV. 25, 2,399,807 Jones May 7, 1946 UNITED STATES PATENTS V FOREIGN PATENTS Number Name Date 533,265 Scholer Jan; 21, 1896 umb r Country Date 1,253,680 Giern et a1 1 Jan. 15, 1918 47.843 Sweden 6; 1920 1,309,217 Ratheram July 8, 1919' 

